Contents

Executive Summary

Throughout the duration of the Fall 2011 semester, this report has been constructed to describe the process of dissecting, analyzing, and reassembling the Toro CCR 2400 E GTS Snow-blower. The project was split into five Gates to separate the process into related objectives. This summary will provide a brief outline of the project and will highlight some of the important points in each section.

\'\'Gate 1\'\': Project Planning – During the project planning phase, a project management proposal was drafted to assess our team’s strengths and weaknesses and to create formal procedures for handling team issues and conflicts that might arise. A point of contact was established and each team member was assigned specific responsibilities. These responsibilities were useful in dividing the work amongst the four members, but it was found that there was often work that felt beyond the range of duties initially accounted for in the assigned positions. An initial dissection procedure was created by studying the visible components and hypothesizing about what interior components might lie beneath the snow-blower casing based on our initial research and understanding of two-cycle gas engines. The snow-blower’s usage and complexity were studied in detail and a product alternative profile was created to demonstrate some other options that achieve the same product function of snow removal.

\'\'Gate 2\'\': Product Dissection – In the product dissection phase, the snow-blower was dismantled into 329 individual components. The disassembly process was thoroughly documented and each step was assigned a difficulty rating. Our group found that the best way to perform this task was to have two people document the disassembly, one wrote each step while the other took pictures and labeled the parts to be put in containers. The other two members then worked together to find the necessary tools and removed the fasteners that hold the snow-blower components together. This recipe was found to be highly successful and was repeated in the product reassembly, Gate 4.

\'\'Gate 3\'\': Product Analysis – In the product analysis phase, the individual components of the snow-blower were analyzed for part geometry, manufacturing methods, and complexity of the geometry and interactions with other components. By performing these studies, the manufacturing processes were reinforced and conclusions were made that connected the Four Factors to the design of the significant components. In this gate, three important components of the engine were modeled using Autodesk Inventor. Additionally, an Engineering Analysis was performed to calculate the convection of heat from the engine heat sink to the surrounding environment. This information could be used to help drive possible redesigns of the engine block and the surrounding exterior casings.

\'\'Gate 4\'\': Product Explanation – During the product explanation phase, the snow-blower was reassembled and the process was compared to the original assembly as well as to our initial disassembly of the device. Throughout the disassembly, the roles assigned to each group member reflected those seen in the Gate 2 disassembly of the Snow-blower. This allowed for proper documentation of each step and a clear comparison between our reassembly, and the original product assembly. Three design revisions are suggested with the Four Factors as the redesign motivation.

\'\'Gate 5\'\': Delivery - The last phase of this project is the conveyance in which all the deliverables were finalized. A four minute presentation was prepared to be given to the class and the instructors that introduced the Toro Snow-blower and highlighted the design recommendation of reconfigurable handle bars based on our considerations of the Four Factors.

This project demonstrates an application of engineering principles learned in class by our group to analyze a practical product. Throughout the project’s completion, a myriad of skills covered in the Intro to Mechanical Engineering Principles class curriculum were used in each deliverable. This fact can be seen from the analysis problems applied to the Snow-blower’s design up to the assigning of manufacturing methods to each part on the product. Finally, this project also increased each group member’s ability to work as a team. This was due to the fact that as frequent challenges presented themselves, we were forced to adapt and work collectively to overcome them.

Project Overview

For MAE 277 Group 6 was tasked to dissect and analyze the internal workings of the Toro CCR 2400 E GTS Snow-blower. The process was documented in a professional fashion. The final technical reports have been compiled in the form of five separate Gates.